OBD Diagnostic Strategies for LEVIII Exhaust Gas Aftertreatment Concepts

With the gradual tightening of light-duty vehicle emission regulations, the fault diagnosis function of the on-board diagnostic (OBD) system is constantly improving and the monitoring items are also increasing. The production vehicle evaluation (PVE) test problem of latest OBD certification in the China VI emission regulations for light vehicles is studied. Firstly, the working principle and development process of OBD system is introduced. Secondly, the PVE testing regulations and testing process of OBD system is analyzed. It covers standardized verification (J1), monitoring requirement verification (J2) and in-use monitoring performance verification (J3). Finally, in order to improve the efficiency of PVE testing for such a large number of faults, a faults classification method based on fault type and function is proposed. OBD faults can be simplified into the six categories, which include circuit fault, tool performance fault, hardware performance fault, bus communication fault and exemption test fault. The simulation method of corresponding fault is introduced and analyzed as well.

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Using In-Vehicle Monitoring Data to Assess Road Conditions of Traffic Flows

Chernyaev

Evtyukov

2022

Mir transp.

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Developments in adaptive systems for maintenance and repair of automotive vehicles set the task of monitoring the conditions of their operation. One of the main factors determining these conditions is the type of road surface.The article describes the results of identification of the type (and condition) of the road surface obtained by theoretical and experimental methods based on the analysis of vertical accelerations recorded on the vehicle body.The purpose of research was to provide a possibility of continuous monitoring of the type of road surface on which a vehicle is driving, with the subsequent application of the obtained data to correct maintenance intervals. The results of experiments have shown the dependence of the vertical acceleration of the body on the micro-profile of the road surface. The described experimentally obtained profiles of vertical accelerations refer to different types of road surface in different conditions. For quantitative assessment, it is proposed to calculate the average level of accelerations as an integral average over a certain time interval.The results of the experiments have allowed to substantiate the empirical dependence of the average level of accelerations on speed of a vehicle. Based on this dependence, a method is proposed for recalculating the current values of the average levels of accelerations obtained at different speeds into values adjusted to the base speed to ensure the possibility of their comparison.It is shown that based on the values of average acceleration levels obtained through operation monitoring regarding a previously known type of road surface, it is possible to determine its condition. A short algorithm is formulated for practical implementation and assessment of road conditions of traffic flows. As for hardware, it is proposed not to equip a vehicle with additional sensors but to use operational standard accelerometers as part of in-vehicle emergency call systems, e.g., ERA-GLONASS equipment units.

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OBD Diagnostic Strategies for LEVIII Exhaust Gas Aftertreatment Concepts

Cited by 6 publications

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The mechanism of continuous monitoring of compliance with environmental requirements imposed on vehicles in operation

The mechanism of continuous monitoring of compliance with environmental requirements imposed on vehicles in operation

Research on Production Vehicle Evaluation Method of China VI OBD for Light-Duty Vehicles

Using In-Vehicle Monitoring Data to Assess Road Conditions of Traffic Flows

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